P0401 on Volvo
Exhaust Gas Recirculation Flow Insufficient
P0401 on Volvo vehicles indicates exhaust gas recirculation flow insufficient. Au7o has documented this code across 2 Volvo models — most commonly on S90, XC60. This code means the Exhaust Gas Recirculation (EGR) system is not flowing enough exhaust back into the engine. The EGR system recirculates a small amount of exhaust into the intake to lower combustion temperatures and reduce nitrogen oxide (NOx) emissions; the computer has determined the actual flow is below what it commanded. The most common reason is carbon buildup clogging the EGR valve or its passages. You may notice pinging/knocking, rough idle, or a check engine light, and the car will fail emissions testing. Typical repair costs on Volvo range from $300 to $4,500, depending on the specific model and root cause.
Common Causes of P0401
- •Carbon buildup clogging the EGR valve or passages
- •Stuck or faulty EGR valve
- •Blocked or restricted EGR ports/tubes
- •Faulty EGR temperature or position sensor
- •Faulty DPFE/EGR pressure sensor (on applicable systems)
- •Vacuum leak or failed vacuum control (vacuum-operated EGR)
- •Wiring or connector problems at the EGR valve
P0401 on Volvo by Model
Volvo S90(1 issue)
- Sensus Infotainment System Lag, Crashes, and Black Screen2017-2023
The Sensus infotainment system in the S90 suffers from significant lag, screen freezes, and black screen episodes. Since the system controls climate, seat heating, navigation, and vehicle settings through the central touchscreen, a crash renders many vehicle functions inaccessible. The system runs on a Tegra K1 processor that struggles with the software load, especially when running multiple features simultaneously. Volvo has released numerous software updates, and the transition to Google-based Android Automotive OS in 2024 addressed the hardware limitations but introduced new software bugs.
Volvo XC60(2 issues)
- Aisin TF-80SC 8-Speed Transmission Shudder and Harsh Shifting2018-2022
The Aisin Warner TF-80SC 8-speed automatic transmission used in the XC60 T5 and T6 can develop shuddering during light acceleration at 30-50 mph and harsh 1-2 and 2-3 upshifts. The torque converter lockup clutch is the primary culprit, with fluid degradation accelerating the issue. The transmission control module (TCM) software has been updated multiple times by Volvo to address shift quality. Some units require torque converter replacement. The issue is more prevalent in vehicles driven primarily in stop-and-go traffic.
- Four-Corner Air Suspension Compressor and Strut Failure2018-2024
XC60 models equipped with the optional Four-C (Four-Corner) air suspension system can experience compressor failure and air strut leaks, typically after 60,000-80,000 miles. The air compressor works overtime to compensate for slow leaks in aging air struts, eventually burning out. Symptoms start with the vehicle sitting lower on one corner after sitting overnight and progress to complete suspension failure with the car sitting on the bump stops. Cold weather accelerates air spring rubber degradation. The system uses Continental air struts.
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View P0401 across all makes →Frequently Asked Questions
What does P0401 mean on Volvo?▼
P0401 stands for "Exhaust Gas Recirculation Flow Insufficient." This code means the Exhaust Gas Recirculation (EGR) system is not flowing enough exhaust back into the engine. The EGR system recirculates a small amount of exhaust into the intake to lower combustion temperatures and reduce nitrogen oxide (NOx) emissions; the computer has determined the actual flow is below what it commanded. The most common reason is carbon buildup clogging the EGR valve or its passages. You may notice pinging/knocking, rough idle, or a check engine light, and the car will fail emissions testing. On Volvo specifically, this code is documented across 2 models.
What causes P0401 on Volvo vehicles?▼
Common causes on Volvo: Carbon buildup clogging the EGR valve or passages, Stuck or faulty EGR valve, Blocked or restricted EGR ports/tubes, Faulty EGR temperature or position sensor, Faulty DPFE/EGR pressure sensor (on applicable systems). Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0401 on a Volvo?▼
Repair costs on Volvo range from $300 to $4,500, depending on the specific model and root cause.
Which Volvo models have P0401 documented?▼
Au7o has documented P0401 on 2 Volvo models: S90, XC60.